Pressure gauge



Nov. 26, 1946. F. w. DwYER PRESSURE GAUGE Filed lJuly s,r 1945 INVENToR ijs W w I Uw im wxs-n.1.

INN l" Patented Nov. 26, 1946 UNITED STATES PATENT OFFICE I 2,411,508 I PRESSURE GAUGE FrankvW. Dwyer, Chicago, Ill. Application July 3, 1943, Serial N0.493,379

vision of a new andimproved gauge having-novel liquid traps :for preventing theff escape of the liqeuidA in the indicatingY column when. th'epressure or suction exceeds a predetermined amount; i;

A 'still'.further. object of the: inventionisf the provision fof a new `and.` improved'.gauge that is' simple in 'constructiomeicienti and accurate in use, that is easily assembled and. adjusted, and'r that is provided with simple and. efficient means for preventing the escape ofthe indicating liduid .in :event thefpressure or suction:exceeds` the capacityofthe gauge;

v.Other and further objects and advantagesrof they invention willappeai-.fromf the following description, taken in connection with the: accom-V panying drawing, .in which. 3 Fig; l is a perspective View of the device;`

Fig'. 2 is a sidek elevation vofthe ndicator'fluid container, Vdetached from the; supporting board;y Fig. 3 is an enlarged verticalsectional Aview of: on'eof the reservoirs; showing th'e'trap valve. in position. therein; andr'i: f "Fig, 4y is a perspective' viewfof the 'lowe'l portion with partsrbroken away."

12Y claims. (c1. 73401) the board and at an acute angle from the channel I5, and in communication with saidl channel, isa groove I6 for receiving the other arm of the indicating tube, as will hereinafter appear.

The front end of the board or sup-port Il is provided4 with a recess l1 extending vertically, that is, transversely to the board; and mounted nthis recess is a reservoir block l5, of suitable material, forcontaining' the indicating liquid.

Preferably, though not necessarily, this reservoir is ofplastic material and transparent, For the purpose of this application it may be considered as being made from a blocky oi Lucitel (thermoplastic methyl methacrylate resin). As shown, the block I8 isprovided with a bore I9 extending longitudinally of the block and' enlarged atits lower end. This enlarged portionv of the bore is Y adapted to contain a liquid'zl, which maybe, and

preferably: is, a suitablelight'oil colored red or some other suitable color,'as may be desired. The bore I9 extends to the upper end of the block I`8,-'an d its intermediate lportion is restricted in diameter to form ashoulder 22 adjacent to the upper end of the board.

The block I8 is slidably mounted in the' groove I1, ,and/'is adapted. tube raised and lowered by the mechanism shown in Fig. 4 that will now be described. Mounted on the lower end ofthe block- 8 is a plate 23 which is rigidly secured to the block,`as by means of the'screw 24, The plate 23 extends laterally into a counter-recess 25 formed-in the botto-moi the Vrecess l1, as shown' moreA clearly in Fig. 4. Attachedr to the bottom Y Vend of; the board ll; vas by means of a screw 26,

is a plate 27, havingan opening in its forward ,end throughqwhicn a screw 28 extends.A Thek Y screkwf28has .mounted thereon4 the nuts29 above Referring now to the drawing, the `reference y character. Hldesignates. the 'pressure gauge which comprises a V'supportingwall l-'Ill adapted4 tot be vertically arranged and held` iiiuprightposit-ion by' means ofra bar'l2, 'which extends transversely of. what-:for convenience y of 1 description will fbe bars 13,44; which extend vertically' across .thev ends thereof andare -r The .lower portion of the board 'I Iv is 'routed out or recessed to form a wide channel I5 extend-'f the plate' 2,1, andv the latter is held between the nuts 2 9' and a shoulder 3|` on the. lowerk en drofr the'screwzs, which holds, the screw from verti,v cal movement@ The screw is adapted to engage a rscrevv-threaclk-ed opening vin theY plateY 23', so thatf'when theknurled'` head 32 of the screw is rotated it' win cause the plate 23 and tht-block I8 yto be raised and lowered for positioning the 1 meniscus 'o f theliquid column, as will ypresently igidly secured 'totlie'iboar'd so* ing lengthwise tothe boardfadjacent its 'ilofwer end, to provide a Aclearanceioi' a portion offtlie indicatingY tube', as will? presently' appear. Ex-

' appear.

The recess jl'l isenlarged in width at its-upper end, andis adaptedto receive, in addition tov the blocki I8, V`a short block 34 having a bore therein for7 forming afcha'mber 35, 'as shown in dot-ted lines in Fig.y l, vThe block 35%, lwhich maybe termeditlfle terminal block, restson the ledge y formed by theenlargement lofthe upper end of tendingiia,,f'o1fiallyl upward from-the outer;endet-I 552 the recess yILl The: terminalblock, 34; and'. block I8 are held in position by a lo-op strap 35, extending over the same, as shown in Fig. 1. This loop his snugly enough to hold the terminal block 34 from movement and at the same time permit vertical movement o the block I3. The terminal chamber 35 and the main reservoir I9 are connected together and are in communication with each other through an indicator tube member 3l, which is located in the channel I5 and groove I5. The tubular member 31 comprises a substantially horizontal portion 38 and an inclined portion 39, which together form a V or an acute angle 43, with one side substantially horizontal. The inclined portion 39 is rigidly held in the groove I3, as by means of suitable clips 4I.

The section 39 of the angular tube member 31 is fixed within the groove, while the section 38 may be iiexed, The tubular indicating member 31 may also be of Lucite, or any other suitable transparent plastic. One end of this member is in communication with the lower end of the reservoir I9, and the upper end is in communication with the lower end of the chamber 35 through suitable passages in the blocks I8 and 34, respectively, A graduated pressure scale 50 is provided back oi the inclined arm 31 for indicating pressure. The graduations are made with the board in upright position, with the top edge substantially horizontal, and in order that the readings shall be accurate it is necessary to level the board before taking readings. A spirit level 33 is mounted on the board I I for leveling the same preparatory to making tests.

Suitable means are provided for preventing loss of the indicating fluid when the pressure exceeds the capacity of the gauge. The two blocks 34 and I8 are each provided at their upper ends with a trap valve, and since the two valves are duplicates of each other only one need be -described.

As-shown in Fig. 3, the block 34 is internally threaded at its upper end for receiving a closure or stopper 42a, formed of a Suitable material, such as plastic or the like. This closure is provided with an enlarged axial recess 43a for detachably receiving the end of a tubular connector meme ber 44, the opposite end of which has attached to it av rubber tube d5. Theopposite end of the rubber tube has a tubular member attached thereto that is not seriously affected by heat or chemicals in the air, and that is adapted to be inserted in a chimney, or the like, for taking the readings of either pressure orsuction. Since this arrangementis so well known to the art it is not felt necessary to illustrate or describe the same more in detail.

A gasket 45V may be provided between the closure or stopper 42a and a shoulder 41 on the interior of the bore 43 of the block 34. The opening 43a extends axially of the closure or stopper 42a, and is provided adjacent its lower end with a restricted portion 49 for receiving the valve or stem I of a valve 52, which is adapted to close the opening 49 and prevent the escape of the liquid when the same -fills the chamber 35. The valve 52 is concave upwardly and is of suitable resilient, comparatively thin, flexible material, such as neoprene (chloroprene rubber), or any other suitable material not affected by the liquid. By making the valve concave and of comparatively thin and resilient material, it is readily distorted to make a'seal even though the stem be not exactly perpendicular. This is considered an important feature of the invention.

In order to guide'the valve stem into the o`penV ing 49, in assembling the parts, the lower end of this opening may beared downwardly and outwardly, as shown at 53. A float 54, of suitable material, is provided for raising the valve to its closed position by the liquid entering the chamber 35. As shown, the float 54 is of cork or like material, and extending through the vertical axis thereof is a tubular member 55, into whichthe lower end of the valve stem 5I is adapted to extend for guiding the valve..

In order that the liquid that may expand into the chamber 35 shall escape back into the tube 39, the lower end of the float 54 has inserted therein a plurality of pins 54a which extend downwardly and outwardly around the lower end of the float, and are adapted to engage the shoulder 5B formed in the upper end of the block 34, shown more clearly in Fig. 3. When the retreat of the liquid downward from the chamber 35 causes lowering of the float 54 to relieve the thin rubber disc or valve 52 of sealing pressure, the valve tends to drop out of its sealing position by gravity and this tendency is desirably augmented by the weight of the pin forming the valve stem 5I, the Weight of the pin being exerted against the rubber valve.

Suitable means are provided for leveling the gauge preparatory to taking readings from the same. In the construction-shown, the bottom end part of the inner end of the board II is provided with a laterally extending plate 56a, which is rigidly attached to the board, as by means of the screws 51. The plate 55a is provided with a screw-threaded opening adapted to be engaged by a screw 58, having va thumb-piece 59 thereon, and a supporting leg 60 extending downwardly therefrom whereby the screw may be turned for raising or lowering the front end of the board Il. The level 33 will indicate the correct position of the board when the same has been adjusted by the thumb-piece 59.

The board II may be provided with means whereby the same may be permanently attached to the wall of a factory building, or the like. In order to attach the gauge to a factory wall, or the like, the board Il is provided with an opening 62 at one end for the reception of a screw, and at its other end with a slot 63 whereby the board may be adjusted to level position, as indicated by the bubble in the level 33. It is necessary, of course, to remove the support I2 before attaching the board I I to the wall of the factory, or the like. It may be necessary at times to replenish the liquid in the reservoir I9, and in order that this may be done without removing the plugs 42 andY 42a the block I8 may be provided adjacent its upper endI with a rthreaded opening extending into the bore, and whichmay be closed by a screw B4.

The blocks I8 and 34, together with the anguular tube connection 31, constitute what may be termed the indicator unit. Any suitable means may be employed for supportingr this unit. While the arm 38 is shown vas being substantially horizontal, this is not necessary since this arm merely constitutes an addition to the capacity of the reservoir I9.v It is only necessary that the parts be so mounted that when in reading position the level of the liquid in the reservoir I9 shall be in the plane of the meniscus of the tubular member 39.

When it is desired to determine the draft of a chimney, for instance, the connector 44 is inserted in the bore 43a of the stopper 4?.a of the block `34,- the board II is adjusted to its level po-V lthe arm 39.'`

sitionbymeans'- of the thumb nut tit-l,A andthe meni's'cuvs lof4 theY liquid column in thev indicator arm-,Bilisladjusted vto Zero-by turning the thumbpie'ce 32-to eitherl raise or lower the block I-8 as the' casema'y be, toV theadjus'tedposition: The free end of the"tu-bef45,'A `Whichis vprovided With aL rigid extension used insuch constructionais thenjplace,d'in` the draft of? thej chimney, andthe draftwill exhaust air fromabove the liquidA in The-pressureV ofv air on the liquid 2 If inthe reservoir' i9 will force the liquid up the inclined passagejj until an equilibrium is ea'chedgafterjwhich thefreading-is made Yon the scaievsu'aiongtne sfide-,0f the' armas;`

n' measuring" pressure' theiconnector `dllI is' 'inserte'd in thelopening 43 in the stopper 42. f `While use withthe connector-fin` the opening 43% the opening""43imust"not be'closed. When not in use. the" passages 43 and 43a'are closed by suitable stoppers for preventing the escapefof the indicator liquid i9, should the board be tilted or laiddown iiat. Y

It is'thought from the foregoing, taken in connection with the accompanying drawing, that the'construction and-operation of my device will .be apparent to those skilled in the art, and that changes in size, shape, proportion and detail may `be made without departing from the spirit andy scope of the appended claims.

Iclaim as my invention: i e

1..In a pressure gauge, an upstanding supporting member, a reservoirY vertically adjustable thereon, a co-nduit in communication with said reservoir and in the form ofY an angle with one side extending diagonally upwardly and laterally, and rigidly secured to said member, said conduit being of Aflexible material and transpari ent, said reservoir and conduit being adapted to contain a liquid, a scale associated with said conduit graduated to indicate the pressure on said reservoir, and means iorrvertically,adjusting said reservoir by iiexing said conduit for adjusting the meniscus of the liquid in said conduit to zero on said scale.

2. In a draft gauge, a block ci plastic Inaterial having a bore leading to a chamber therein, said chamber having an abutment in the lower portion thereof and an upwardly extending opening, a stopper for said'opening having a passage therethrough, a valve forfclosing said passage from the inside, said valve comprising a valve, stem insertable in said passage for guiding said stern, a concave resilient iiexible valvek for seating over'said passage xed on said stem, a lloat having a passage therethrough for receiving the lower end of said stem, and pins extending down from said float for engaging said abutment forl preventing said stopper from closing said borey when said chamber is in upright position.

3. A pressure gauge comprising an upright base board having a channel across-its lower edge portion and having a groove extending upwardly and forwardly from the outer end of said channel, a vertical recess across the inner edge of said board and extended laterally at its upper end,` a block vertically adjustable in said recess and Ahaving a reservoir therein in communication with the atmosphere at its upper end, a second block having a chamber therein in the lateral extensionYV of said'recess, said chamber beingvin communication with the atmosphere at its uppermost partv thereof, a conduit capable of' being iiexed having atransparent portion in theform of an acute angle having one arm'extending along said channel and movable therein and the other valong 6 said groove; said conduit being in communication with saidreservoir and chamber and being adapte edto-containan indicating liquid, a valve in said chamber for preventing the escape of'liquid therefrom, a vscale along said inclined arm, a connector means for conducting `pressure to'said reservoir, a port above said reservoir in said rstnamed-block throughv which an indicatingV liquid may be'introduced to said reservoir, and -a clo- 'sureforsaid-port.

-4'17In a pressuregauge, a block having a chamber therein,- a stopper for closing the upper end of said chamber, an axial opening extending through said Stopper and vadapted tolreceive a connector member, a valve comprising a thin concave flexible ymember of'elastic material, a

iioat for' elevating said member over said opening for closingthesame when the indicating fluid rises above a predetermined heightw'itlun said chamber, and a guide stem for said float'.

`5. 'In'a pressure gauge, a reservoir, a Support for lthe same, an indicating tube having a, ilexiblgportion' in the form rof an acute angle having one arm iii'mlyconnected to Asaid reservoir and extending outwardly, therefrom and the other arm connected to the outer end of the firstnamed arm and extending upwardly and laterally therefrom, means for rigidly securing theY inclined arm to said support, means for raising y andlowering said reservoir and exing said tube,

andV a scale extending along said inclined arm.

6. In a draft gauge, a reservoir for containing 1 an indicating liquid, a support therefor, a passage of flexible material connected to the lower portion of said reservoir and extending laterally therefrom and then diagonally upwardly above said reservoir, means for elevating said reservoir independently of said support, the inclined portion of said passage lbeing xed to said support whereby when said reservoir is elevated said passage is iiexed, and means for l port.

ing the upper end of said chamber, an axial opening extending throughsaid stopper and adapted lto receive a connector member, said chamber comprising a trap including a valve member, a float for elevating said valve member for clos- Y ing said opening when the uid in said chamber rises above a predetermined amount, and a plurality of spaced apart pins extending downwardly from said float for supporting said float above the bottom of said chamber when there is not umcient liquid in said chamber to support said oat. A

8. In a pressure gauge, a chamber having an opening to the atmosphere, a support, a reservoir on said support for containing an indicating liquid, a tube flexibly interconnecting said chamber and reservoir, means for ing said reservoir on said sup being above the bottom of said having a transparent portion, with said transparent portion liquid level therein, a closure forsaid opening witliinsaid chamber, and a oat for elevating said closure for closing said opening when the indicating iiuid risesV above a. predetermined height Within said chamber.

9. An indicator unit for a pressure gauge comprising a reservoir, a chamber, a liquid-containing tube of transparent material arranged in the form of an angle' with one arm extending upport, said chamber a scale associated for indicating the eveling said sup- '7.V InI a pressure gauge, a block having a bore f leading to a chamber therein, a Stopper for closraising and lowerreservoir, said tube .v y

wardly and laterally to said chamber and the other arm connected with said reservoir, said other arm being flexible to permit relative vertical movement between said chamber and said reservoir, and adjustment means for causing relative vertical movement between said chamber and said reservoir to vary the liquid level in said first-mentioned arm of the tube.

l0. An indicator unit for a pressure gauge comprising a reservoir, a chamber, a liquid-containing passage means interconnecting said reservoir and said chamber, said passage means being in the form of an angle with a fixed upwardly and laterally extending transparent arm connected to said chamber and with a exible arm connected to said reservoir, means for raising and lowering said reservoir with consequent ilexure of said passage means, and means within said chamber for preventing loss oi liquid therefrom.

11. In a pressure gauge, a reservoir, a uidcontaining indicator tube having one end connected to said reservoir, a chamber connected to the other end of said tube for receiving overflow liquid therefrom, said chamber having an opening of reduced diameter in its upper wall, a closure in said chamber for said opening comprising a flexible resilient concave disc, and a float member for elevating said disc When the liquid rises within said chamber to a predetermined level, said disc and float member being structurally separate for independent movement and separate replacement when necessary.

l2. In a pressure gauge, an upwardly extending passagecontainng a column of non-metallic liquid movable therein in response to pressure changes, a normally open vent port at the upper end of said passage, a oat body in said passage movable towards said vent port in response to approach of the liquid column to the port, means including a perforated resilient member for establishing a seal to out o said vent port in response to rise of said float body, said means including also a weighted member for sealing off the perforation in the resilient member and being adapted by its weight to open said seal when said float body moves downward away from the vent port.

FRANK W. DWYER` 

